Serial/Series Title
Chemical Processing Department Monthly Report
15
Fiscal Year 2004
3
Fiscal Year 2005
3
Fiscal Year 2001
2
Fiscal Year 2007
2
Irradiation Processing Department Monthly Record Report
2
A Novel Membrane Reactor for Direct Hydrogen Production From Coal Progress Report
1
A Real-Time Coal Content/Ore Grade (C2OG) Sensor, Technical Report
1
BEETIT Program
1
Carbon Sequestration on Surface Mine Lands Quarterly Report
1
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3,101 Matching Results
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Development of a video-based slurry sensor for on-line ash analysis. Eighth quarterly technical progress report, July 1, 1996--September 30, 1996
Automatic control of fine coal cleaning circuits has traditionally been limited by the lack of sensors for on-line ash analysis. Although several nuclear-based analyzers are available, none have seen widespread acceptance. This is largely due to the fact that nuclear sensors are expensive and tend to be influenced by changes in seam type and pyrite content. Recently, researchers at VPI&SU have developed an optical sensor for phosphate analysis. The sensor uses image processing technology to analyze video images of phosphate ore. It is currently being used by PCS Phosphate for off-fine analysis of dry flotation concentrate. The primary advantages of optical sensors over nuclear sensors are that they are significantly cheaper, are not subject to measurement variations due to changes in high atomic number minerals, are inherently safer and require no special radiation permitting. The purpose of this work is to apply the knowledge gained in the development of an optical phosphate analyzer to the development of an on-fine ash analyzer for fine coal slurries. During the past quarter, installation of the video-based ash analyzer at the Middle Fork plant site was completed. A method of measuring and automatically adjusting for small variations in the sensor illumination scheme was developed …
Date:
October 22, 1996
Creator:
Adel, G. T. & Luttrell, G. H.
Object Type:
Report
System:
The UNT Digital Library
Development of a video-based slurry sensor for on-line ash analysis. Quarterly report, April 1, 1996--June 30, 1996
Automatic control of fine coal cleaning circuits has traditionally been limited by the lack of sensors for on-line ash analysis. Although several nuclear-based analyzers are available, none have seen widespread acceptance. This is largely due to the fact that nuclear sensors are expensive and tend to be influenced by changes in seam type and pyrite content. Recently, researchers at VPI&SU have developed an optical sensor for phosphate analysis. The sensor uses image processing technology to analyze video images of phosphate ore. It is currently being used by PCS Phosphate for off-line analysis of dry flotation concentrate. The primary advantages of optical sensors over nuclear sensors are that they are significantly cheaper, are not subject to measurement variations due to changes in high atomic number minerals, are inherently safer and require no special radiation permitting. The purpose of this work is to apply the knowledge gained in the development of an optical phosphate analyzer to the development of an on-line ash analyzer for fine coal slurries. During the past quarter, an industrially-hardened version of the video-based ash analyzer was designed and constructed. All components are now in place at the Middle Fork plant site awaiting the installation of a sample line …
Date:
July 22, 1996
Creator:
Adel, G. T. & Luttrell, G. H.
Object Type:
Report
System:
The UNT Digital Library
Progress on H5Part: A Portable High Performance Parallel DataInterface for Electromagnetics Simulations
Significant problems facing all experimental andcomputationalsciences arise from growing data size and complexity. Commonto allthese problems is the need to perform efficient data I/O ondiversecomputer architectures. In our scientific application, thelargestparallel particle simulations generate vast quantitiesofsix-dimensional data. Such a simulation run produces data foranaggregate data size up to several TB per run. Motived by the needtoaddress data I/O and access challenges, we have implemented H5Part,anopen source data I/O API that simplifies the use of the HierarchicalDataFormat v5 library (HDF5). HDF5 is an industry standard forhighperformance, cross-platform data storage and retrieval that runsonall contemporary architectures from large parallel supercomputerstolaptops. H5Part, which is oriented to the needs of the particlephysicsand cosmology communities, provides support for parallelstorage andretrieval of particles, structured and in the future unstructuredmeshes.In this paper, we describe recent work focusing on I/O supportforparticles and structured meshes and provide data showing performance onmodernsupercomputer architectures like the IBM POWER 5.
Date:
June 22, 2007
Creator:
Adelmann, Andreas; Gsell, Achim; Oswald, Benedikt; Schietinger,Thomas; Bethel, Wes; Shalf, John et al.
Object Type:
Article
System:
The UNT Digital Library
105-DR Large Sodium Fire Facility closure activities evaluation report
This report evaluates the closure activities at the 105-DR Large Sodium Fire Facility. The closure activities discussed include: the closure activities for the structures, equipment, soil, and gravel scrubber; decontamination methods; materials made available for recycling or reuse; and waste management. The evaluation compares these activities to the regulatory requirements and closure plan requirements. The report concludes that the areas identified in the closure plan can be clean closed.
Date:
April 22, 1996
Creator:
Adler, J. G.
Object Type:
Report
System:
The UNT Digital Library
Advances in Normal Conducting Accelerator Technology from the X-Band Linear Collider Program
In the mid-1990's, groups at SLAC and KEK began dedicated development of X-band (11.4 GHz) rf technology for a next generation, TeV-scale linear collider. The choice of a relatively high frequency, four times that of the SLAC 50 GeV Linac, was motivated by the cost benefits of having lower rf energy per pulse (hence fewer rf sources) and reasonable efficiencies at high gradients (hence shorter linacs). To realize such savings, however, requires operation at gradients and peak powers much higher than that hitherto achieved. During the past twelve years, these challenges were met through innovations on several fronts. This paper reviews these achievements, which include developments in the generation and transport of high power rf, and new insights into high gradient limitations.
Date:
June 22, 2005
Creator:
Adolphsen, C.
Object Type:
Article
System:
The UNT Digital Library
Cesium Ion Exchange Using Tank 241-AN-104 Supernate
The River Protection Project is to design and build a high level nuclear waste treatment facility. The waste treatment plant is to process millions of gallons of radioactive waste stored in tanks at the Hanford Site. The high level nuclear waste treatment process includes various unit operations, such as ultrafiltration, precipitation, evaporation, ion exchange, and vitrification. Ion exchange is identified as the optimal treatment method for removal of cesium-137 and Tc-99 from the waste. Extensive ion exchange testing was performed using small-scale columns with actual waste samples. The objectives of this study were to: demonstrate SuperLig 644 ion exchange performance and process steps for the removal of cesium from actual AN-104 tank waste; pretreat actual AN-104 tank waste to reduce the concentration of cesium-137 in the waste below LAW vitrification limit; produce and characterize cesium eluate solutions for use in eluate evaporation tests. The experiments consisted of batch contact and small-scale column tests. The batch contact tests measured sorption partition coefficients Kds. The Kds were used to predict the effective resin capacity. The small-scale column tests, which closely mimic plant conditions, generated loading and elution profile data used to determine whether removal targets and design requirements were met.
Date:
December 22, 2003
Creator:
Adu-Wusu, K.
Object Type:
Report
System:
The UNT Digital Library
EVALUATION OF POTENTIAL ELUANTS FOR NON-ACID ELUTION OF CESIUM FROM RESORCINOL-FORMALDEHYDE RESIN
Small-column ion exchange (SCIX) units installed in high-level waste tanks to remove Cs-137 from highly alkaline salt solutions are among the waste treatment plans in the DOE-complex. Spherical Resorcinol-Formaldehyde (sRF) is the ion exchange resin selected for use in the Hanford Waste Treatment and Immobilization Plant (WTP). It is also the primary ion exchange material under consideration for SCIX at the Hanford site. The elution step of the multi-step ion exchange process is typically done with 0.5 M nitric acid. An acid eluant is a potential hazard in the event of a spill, leak, etc. because the high-level waste tanks are made of carbon steel. Corrosion and associated structural damage may ensue. A study has been conducted to explore non-acid elution as an alternative. Batch contact sorption equilibrium screening tests have been conducted with 36 potential non-acid eluants. The sorption tests involve equilibrating each cesium-containing eluant solution with the sRF resin for 48 hours at 25 C in a shaker oven. In the sorption tests, an eluant is deemed to have a high cesium elution potential if it minimizes cesium sorption onto the sRF resin. The top candidates (based on lowest cesium sorption distribution coefficients) include ammonium carbonate, ammonium carbonate/ammonium …
Date:
December 22, 2010
Creator:
Adu-Wusu, K. & Pennebaker, F.
Object Type:
Report
System:
The UNT Digital Library
Supporting collaborative computing and interaction
To enable collaboration on the daily tasks involved in scientific research, collaborative frameworks should provide lightweight and ubiquitous components that support a wide variety of interaction modes. We envision a collaborative environment as one that provides a persistent space within which participants can locate each other, exchange synchronous and asynchronous messages, share documents and applications, share workflow, and hold videoconferences. We are developing the Pervasive Collaborative Computing Environment (PCCE) as such an environment. The PCCE will provide integrated tools to support shared computing and task control and monitoring. This paper describes the PCCE and the rationale for its design.
Date:
May 22, 2002
Creator:
Agarwal, Deborah; McParland, Charles & Perry, Marcia
Object Type:
Article
System:
The UNT Digital Library
High efficiency, radiation-hard solar cells
The direct gap of the In{sub 1-x}Ga{sub x}N alloy system extends continuously from InN (0.7 eV, in the near IR) to GaN (3.4 eV, in the mid-ultraviolet). This opens the intriguing possibility of using this single ternary alloy system in single or multi-junction (MJ) solar cells of the type used for space-based surveillance satellites. To evaluate the suitability of In{sub 1-x}Ga{sub x}N as a material for space applications, high quality thin films were grown with molecular beam epitaxy and extensive damage testing with electron, proton, and alpha particle radiation was performed. Using the room temperature photoluminescence intensity as a indirect measure of minority carrier lifetime, it is shown that In{sub 1-x}Ga{sub x}N retains its optoelectronic properties at radiation damage doses at least 2 orders of magnitude higher than the damage thresholds of the materials (GaAs and GaInP) currently used in high efficiency MJ cells. This indicates that the In{sub 1-x}Ga{sub x}N is well-suited for the future development of ultra radiation-hard optoelectronics. Critical issues affecting development of solar cells using this material system were addressed. The presence of an electron-rich surface layer in InN and In{sub 1-x}Ga{sub x}N (0 < x < 0.63) was investigated; it was shown that this is …
Date:
October 22, 2004
Creator:
Ager, J. W., III & Walukiewicz, W.
Object Type:
Report
System:
The UNT Digital Library
Experiments on Antiprotons: Cross Sections of Complex Nuclei
Experiments are described that have been designed to measure separately annihilation and reaction cross sections for antiprotons of approximately 450 MeV on oxygen, copper, silver, and lead. A new and more luminous spectrograph has been built for this experiment. The antiproton cross sections a r e compared with total proton cross sections, and are found to be larger by a factor varying from 1.74 for oxygen to 1.39 for silver. Calculations based on the optical model give a reasonable connection between these cross sections and the 6-p and 6-n cross sections. Finally, the information available on antiproton production cross sections is collected. There are indications that a free nucleon is several times as effective as a bound one for producing antiprotons.
Date:
July 22, 1957
Creator:
Agnew, Jr., Lewis E.; Chamberlain, Owen; Keller, Donald V.; Mermod, Ronald; Rogers, Ernest H.; Steiner, Herbert M. et al.
Object Type:
Report
System:
The UNT Digital Library
Stress Corrosion Cracking of Fe--Cr--Ni Alloys in Caustic Environments. Quarterly Report, April 15--July 14, 1970.
None
Date:
July 22, 1971
Creator:
Agrawal, A. K. & Staehle, R. W.
Object Type:
Report
System:
The UNT Digital Library
Stress Corrosion Cracking of Fe--Cr--Ni Alloys in Caustic Environments. Quarterly Report, January 15--April 14, 1970.
None
Date:
July 22, 1971
Creator:
Agrawal, A. K. & Staehle, R. W.
Object Type:
Report
System:
The UNT Digital Library
Development, field testing of a laser instrument for the measurement of sediment reference concentration in the MARGINS Program. Final report
A small grant was added to an ongoing Navy program to extend the scope of ongoing work by development of a new laser instrument. The instrument, MSCAT (Miniature Scattering and Transmissometry) uses small angle scattering to obtain the needed multi-parameter information for measurement of particle size distribution and number density. During the short course of the grant, the instrument was built and tested in a field experiment off the coast of North Carolina. Useful data were obtained, and these have been presented at the Fall Meeting of the American Geophysical Union in 1994.
Date:
May 22, 1998
Creator:
Agrawal, Yogesh C.
Object Type:
Report
System:
The UNT Digital Library
A High Temperature Phase Transition in Weakly Coupled Large N Gauge Theories on a Three-sphere
We argue that weakly coupled 3+1 dimensional large N SU(N) gauge theories, with 't Hooft coupling {gamma}, compactified on a three-sphere of radius R, exhibit a novel second order phase transition at a temperature T{sub c} = C{radical}{gamma} R. The known constant C depends on the details of the gauge theory. The phase transition is characterized by a change in the eigenvalue distributions of the fields. Above the transition, the only eigenvalues which condense are those of the lowest Kaluza-Klein mode of the spatial gauge field Ai on the three-sphere. Below the transition the eigenvalues of the lowest Kaluza-Klein mode of an additional field condense. We discuss in particular the examples of pure Yang-Mills theory and of the N = 4 supersymmetric Yang-Mills theory.
Date:
June 22, 2007
Creator:
Aharony, Ofer & Hartnoll, Sean A.
Object Type:
Report
System:
The UNT Digital Library
Study to define the shock and vibration environment during truck transport of shipping containers. Summary report
None
Date:
December 22, 1971
Creator:
Ahlbeck, D. R.
Object Type:
Report
System:
The UNT Digital Library
RIA R&D for Enabling Direct Neutron Cross-Section Measurements
The expected production rates at RIA imply it should be possible to collect 10-{micro}g of a one-day half-life isotope. The amount of material should be sufficient to enable direct neutron cross-section measurements for many unstable isotopes. This capability is crucial for many of the stockpile stewardship and some of the astrophysical cross-section measurements. Enabling this capability at RIA requires the ability to harvest the desired isotopes, process highly radioactive material into targets, and irradiate targets with neutrons. This paper will discuss the changes and additions to the RIA complex that are necessary in order to enable direct neutron cross-section measurements. This will include a discussion of harvesting as well as a conceptual design for a co-located experimental facility with radiochemistry capability and a variable 'mono-energetic' neutron source.
Date:
August 22, 2003
Creator:
Ahle, L. E.; Rusnak, B. & Stoyer, M.
Object Type:
Article
System:
The UNT Digital Library
Initial experiments of RF gas plasma source for heavy ionfusion
The Source Injector Program for the US Heavy Ion Fusion Virtual National Laboratory is currently exploring the feasibility of using RF gas plasma sources for a HIF driver. This source technology is presently the leading candidate for the multiple aperture concept, in which bright millimeter size beamlets are extracted and accelerated electrostatically up to 1 MeV before the beamlets are allowed to merge and form 1 A beams. Initial experiments have successfully demonstrated simultaneously high current density, {approx} 100 mA/cm{sup 2} and fast turn on, {approx} 1 {micro}s. These experiments were also used to explore operating ranges for pressure and RF power. Results from these experiments are presented as well as progress and plans for the next set of experiments for these sources.
Date:
May 22, 2002
Creator:
Ahle, L.; Hall, R.; Molvik, A. W.; Chacon-Golcher, E.; Kwan, J. W.; Leung, K. N. et al.
Object Type:
Article
System:
The UNT Digital Library
RF gas plasma source development for heavy ion fusion
Presently the Heavy Ion Fusion Virtual National Laboratory is researching ion sources and injector concepts to understand how to optimize beam brightness over a range of currents (50-2000 mA argon equivalent). One concept initially accelerates millimeter size, milliamp beamlets to 1 MeV before merging them into centimeter size, ampere beams. Computer simulations have shown the final brightness of the merged beams is dominated by the emittance growth of the merging process, as long as the beamlets ion temperature is below a few eV. Thus, a RF multicusp source capable of high current density can produce beams with better brightness compared to ones extracted from a colder source with a large aperture and lower current density. As such, experiments have begun to develop a RF multicusp source capable of delivering one amp of extracted beam current. It is expected that it will require 10 kW of 13 MHz RF power delivered via a quartz shielded, one and half turn, four inch diameter antenna. Important considerations in the development of the source include the dependence of current density and beam ion temperature on consumed RF power and gas pressure. A fast rise time ({approx}100 ns) for the extracted beam pulse must also …
Date:
February 22, 2002
Creator:
Ahle, L.E.; Hall, R.P. & Molvik, A.W.
Object Type:
Article
System:
The UNT Digital Library
Nuclear structure studies from prompt gamma-ray spectroscopy of fission fragments.
None
Date:
June 22, 2000
Creator:
Ahmad, I.
Object Type:
Article
System:
The UNT Digital Library
X-ray diffraction diagnostic design for the National Ignition Facility
None
Date:
August 22, 2013
Creator:
Ahmed, M F; Ayers, J; House, A; Lamb, Z; Swift, R & Swift, D
Object Type:
Article
System:
The UNT Digital Library
EARLY ENTRANCE COPRODUCTION PLANT
The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan for implementation in Phase II; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing and testing …
Date:
November 22, 2002
Creator:
Ahmed, Mushtaq; Anderson, John H.; Berry, Earl R.; Brent, Fred; He, Ming; Ong, Jimmy O. et al.
Object Type:
Report
System:
The UNT Digital Library
Fuel processing for fuel cell powered vehicles.
A number of auto companies have announced plans to have fuel cell powered vehicles on the road by the year 2004. The low-temperature polymer electrolyte fuel cells to be used in these vehicles require high quality hydrogen. Without a hydrogen-refueling infrastructure, these vehicles need to convert the available hydrocarbon fuels into a hydrogen-rich gas on-board the vehicle. Earlier analysis has shown that fuel processors based on partial oxidation reforming are well suited to meet the size and weight targets and the other performance-related needs of on-board fuel processors for light-duty fuel cell vehicles (1).
Date:
January 22, 1999
Creator:
Ahmed, S.; Wilkenhoener, R.; Lee, S. H. D.; Carter, J. D.; Kumar, R. & Krumpelt, M.
Object Type:
Article
System:
The UNT Digital Library
Photoconductive properties of GaAs{sub 1{minus}x}N{sub x} double heterostructures as a function of excitation wavelength
The ternary semiconductor GaAs{sub 1{minus}x}N{sub x} with 0 < x < 0.3 can be grown epitaxially on GaAs and has a very large bowing coefficient. The alloy bandgap can be reduced to about 1.0 eV with about a 3% nitrogen addition. In this work, the authors measured the internal spectral response and recombination lifetime of a number of alloys using the ultra-high frequency photoconductive decay (UHFPCD) method. The data shows that the photoconductive excitation spectra of the GaAs{sub 0.97}N{sub 0.03} alloy shows a gradual increase in response through the absorption edge near E{sub g}. This contrasts with most direct bandgap semiconductors that show a steep onset of photoresponse at E{sub g}. The recombination lifetimes frequently are much longer than expected from radiative recombination and often exceeded 1.0{mu}s. The data were analyzed in terms of a band model that includes large potential fluctuations in the conduction band due to the random distribution of nitrogen atoms in the alloy.
Date:
May 22, 2000
Creator:
Ahrenkiel, R. K.; Mascarenhas, A.; Johnston, S. W.; Zhang, Y.; Friedman, D. J. & Vernon, S. M.
Object Type:
Article
System:
The UNT Digital Library
Acoustic Separation Technology
Today's restrictive environmental regulations encourage paper mills to close their water systems. Closed water systems increase the level of contaminants significantly. Accumulations of solid suspensions are detrimental to both the papermaking process and the final products. To remove these solids, technologies such as flotation using dissolved air (DAF), centrifuging, and screening have been developed. Dissolved Air Flotation systems are commonly used to clarify whitewater. These passive systems use high pressure to dissolve air into whitewater. When the pressure is released, air micro-bubbles form and attach themselves to fibers and particles, which then float to the surface where they are mechanically skimmed off. There is an economic incentive to explore alternatives to the DAF technology to drive down the cost of whitewater processing and minimize the use of chemicals. The installed capital cost for a DAF system is significant and a typical DAF system takes up considerable space. An alternative approach, which is the subject of this project, involves a dual method combining the advantages of chemical flocculation and in-line ultrasonic clarification to efficiently remove flocculated contaminants from a water stream
Date:
February 22, 2002
Creator:
Ahrens, Fred & Patterson, Tim
Object Type:
Report
System:
The UNT Digital Library